If you join Amazon in the sky, you needn't build your own database down on earth. "Traditional clustered relational databases often require a sizeable upfront investment and complex design. Our customers have asked us for a simple, scalable, reliable and low-latency alternative," SimpleDB general manager Matt Domo said in a statement.

"Amazon SimpleDB eliminates complexity so that developers and businesses can focus on optimizing applications and not administering their database. We're pleased that we can now make the service available broadly and also pass along the cost savings we've achieved."

Of course, Amazon's clouds have been know to vanish from time to time.

For "at least" the next six months, Amazon will provide a certain amount of free cloud sitting. Every month, SimpleDB users will receive 25 machine hours, 1GB of data transfers in, 1GB of transfers out, and 1GB of storage at no charge. Once those freebies are exhausted, you'll pay $0.14 per machine hour, $0.10 per GB in, $0.10 to $0.17 per GB out, and $0.25 per GB of storage. Storage pricing is down 83 per cent from the cloud's limited beta.

You can also transfer an unlimited amount of data from EC2 at no charge.

Meanwhile, over "the next few weeks," Amazon will equip its SimpleDB cloud with a new API that provides a "SQL-like" query language and a "batch put" function for uploading items en masse. ®